Tweak abstract wording.
Tweak abstract wording.

	* Improve general flow and text arrangement.
	* Prefix some services with 'The'.
	* Expand RHEL to Red Hat Enterprise Linux.

	* Patchset/amend, niceness failed, removed trailing whitespace.

Change-Id: Ic8956282a8b3eddfad0e47296954058bbf457662

gongysh2004/openstack-manual,saeki-masaki/openstack-manuals,openstack/openstack-manuals,Akasurde/openstack-manuals,potsmaster/openstack-manuals,potsmaster/openstack-manuals,openstack/openstack-manuals,kairoaraujo/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,gongysh2004/openstack-manual,kairoaraujo/openstack-manuals,Akasurde/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,saeki-masaki/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals